I cant understand,what advantage we gain by maintaining the multiple copies of the shrad? wht advantage does modified consistent hashing has over consistent hashing.It might sound a dumb question but i am new to the topic :)
With respect to modified consistent hashing, it makes sure that order in which shards follow each other is not deterministic. So if a shard fails the load will not be on a single shard, it will be shared by all subsequent shards that follow the failed instance at different places.
So, is the same instance referenced at different places on the ring or one instance is replicated at different places on the ring? if the same instance is referenced, then it is just a way to divide the load (in case S1 fails) to all the other shards where the replica of S1 is maintained. Is it correct or am I missing something?